But Tesla has a Price/Earnings ratio of 100 while other car companies like Toyota only have a P/E of 10. So Tesla's stock price could drop a long way while still being reasonable.
And if Musk had got a loan against his Tesla stock to buy Twitter, a substantial drop in Tesla's price could have disproportionate results.
I give Gwynne Shotwell a ton of credit for actually running SpaceX on a day to day basis.
I think a lot of the issues with Tesla exist because as far as I can tell Tesla does not have a Gwynne Shotwell.
Then, your "sorta-neat stable business" has MASSIVE amounts of value from stock grants, capital it can use to hire more, pay more, finance debt for large purchases, etc. Kind of a superpower for an otherwise unremarkable company.
Of course, there's other externalities from the buffoon and his cultists. They can drive away good workers, or pivot the company in unpleasant directions, or just leave some day, tank the company stock, and then the company loses the superpower and all of the things that come with it. But if your main mission is growth, well, it makes a lot of sense...